The assault happened in Bank Heys Street in the town centre on Monday, September 11, with the victim left needing hospital treatment for his injuries.
Lancashire Police said it has carried out numerous enquiries to identify the assailant and the force is now asking for the public’s help.
A police spokesperson said: “As seen in the CCTV image, the man was wearing a black long sleeved T-shirt and blue faded jeans.
"If you see him in the street, we would ask that you do not approach him but instead call 999 immediately.
"Anyone who recognises the man – or the man himself – is asked to email email@example.com or 101, quoting log 1048 of September 11, 2023.”